At present the throttle device of air-conditioner with both cooling and warming functions can be divided mainly into both capillary throttle device and expansion valve throttle device. Generally, the capillary throttle device comprises a (or a group of) capillary tube, or a (or a group of) capillary tube connecting in series with another (or a group of) capillary tube connected with a one-way valve in parallel. The former is always throttled by same capillary tube under cooling operation mode and warming operation mode, so that the air-conditioner could not be operated at an optimum condition under above two modes i.e. a cooling and a warming operation mode. Furthermore, it is difficult to give consideration to the two different modes simultaneously for the optimized design of air conditioner. Although the latter can use capillary tubes of different length to throttle for both cooling operation mode and warming operation mode by adjustment and control of one-way valve, it is inconvenient to perform independent optimized design for cooling and warming operation modes of the air-conditioner respectively, because these two (or two groups of) capillary tubes are connected to each other in series. Similarly, the expanding valve throttle device has same problem, i.e. it is difficult to give consideration to two different operation modes simultaneously for optimized design of air-conditioner.